Various head-up display devices in which a vehicle occupant is able to see various information such as navigation information by overlapping with an outside view are proposed, for example, in PTL 1 to PTL3.
The above head-up display device includes an irradiation device for irradiating display light, and a combiner as a reflector for reflecting the display light. The combiner is stored in an instrument panel. As shown in FIGS. 16C and 16D, when upward operation (namely, ON operation) is performed, the combiner is moved to a display position (namely, expansion position) projecting from the instrument panel, and held in the display position. Then, when downward operation, namely, OFF operation is performed, the combiner is moved down, and again stored in the instrument panel.
The movement of the combiner is performed by a motor. As is clear from FIGS. 16A-16F, conventionally, drive torque setting of the motor is maintained constant regardless of whether the combiner is moved, held, or stopped. As the above motor, a motor in which a high current is required with high torque is used because it needs to move the combiner. In order to increase torque of the motor, coil resistance is reduced, and a high current is applied to the coil resistance.
The conventional head-up display device always passes a high current from ignition-ON to ignition-OFF. As a result, a coil of the motor produces heat, resistance is increased, the current is decreased, and thereby the torque is reduced. Furthermore, surrounding resin components are deformed by heat generation of the motor, and thereby failure of the device occurs.